An image forming apparatus has an image forming portion, a fixing device, a temperature sensing device, and a control portion. The fixing device has a fixing member having a heated rotary member and a pressing member forming a fixing nip by making contact with the heated rotary member. The temperature sensing device senses the surface temperature of at least one of the heated rotary member and the pressing member in a plurality of regions in the axial direction. The control portion estimates the thickness distribution of the surface layer of at least one of the heated rotary member and the pressing member in the axial direction based on the time taken for the surface temperature in the plurality of regions to reach the predetermined temperature, and thereby estimates the lifetime of at least one of the heated rotary member or the pressing member based on the estimated thickness distribution.

An image forming apparatus includes: a first image forming unit which forms a first image on a first recording medium with a first material that is not thermally decolorizable; a second image forming unit which forms a second image on a second recording medium with a second material that is thermally decolorizable; a fixing device which is on a common carrying path shared by the first recording medium and the second recording medium and fixes the first image to the first recording medium; and a controller which controls the fixing device so that a temperature of the fixing device is lower than a decolorizing temperature of the second material when the second recording medium reaches the fixing device.

An image forming apparatus includes: a first image forming unit which forms a first image on a first recording medium with a first material that is not thermally decolorizable; a second image forming unit which forms a second image on a second recording medium with a second material that is thermally decolorizable; a fixing device which is on a common carrying path shared by the first recording medium and the second recording medium and fixes the first image to the first recording medium; and a controller which controls the fixing device so that a temperature of the fixing device is lower than a decolorizing temperature of the second material when the second recording medium reaches the fixing device.

An image forming apparatus has an image forming portion, a fixing device, a temperature sensing device, and a control portion. The fixing device has a fixing member having a heated rotary member and a pressing member forming a fixing nip by making contact with the heated rotary member. The temperature sensing device senses the surface temperature of at least one of the heated rotary member and the pressing member in a plurality of regions in the axial direction. The control portion estimates the thickness distribution of the surface layer of at least one of the heated rotary member and the pressing member in the axial direction based on the time taken for the surface temperature in the plurality of regions to reach the predetermined temperature, and thereby estimates the lifetime of at least one of the heated rotary member or the pressing member based on the estimated thickness distribution.

An image forming apparatus includes an image forming device, a container, a thermal fixing device, and a duct. The image forming device forms an image on a sheet with an image forming substance. The container is separate from the image forming device and stores the image forming substance to be supplied to the image forming device. The thermal fixing device applies heat and pressure to the image forming substance to fix the image on the sheet. The duct guides air to flow upward through a first region between an outer circumference of the image forming device and an outer circumference of the container and a second region adjacent to an outer circumference of the thermal fixing device.

A fixing device including a rotatable tubular film, a heater including a substrate and a heat generating resistor, the heater including a first surface in contact with an inner surface of the film and a second surface opposite to the first surface, the heater extending in a longitudinal direction of the substrate, and a heat conducting member extending in the longitudinal direction and including a heater contact portion in contact with the second surface. The heat conducting member includes a film contact portion at a position adjacent to the first surface, the film contact portion being in contact with the inner circumferential surface, and on one side in the longitudinal direction, the heat generating resistor extends outside of a longitudinal end portion of the film contact portion, and the heater contact portion extends outside of the film contact portion.

A fixing apparatus includes a heating rotating member, a pressure rotating member, and a contact member. A contact holding member holds the contact member so that the contact member presses against the heating rotating member, and causes at least a portion of the contact member to elastically deform between the heating rotating member and the contact holding member. In addition, a displacement mechanism displaces a relative position of the heating rotating member with respect to the pressure rotating member. When the heating rotating member is separated from the pressure rotating member by the displacement mechanism, an interval between a fulcrum, at which the contact holding member holds the contact member, and a contact point, at which the contact member comes into contact with the heating rotating member, does not increase.

Provided is a fixing apparatus provided with a displacement mechanism 21 which displaces a relative position of a fixing film 1 which generates heat when energized, with respect to a pressure roller 3, wherein, when the fixing film is separated from the pressure roller by the displacement mechanism, an interval between a fulcrum at which a contact holding member 10 holds a contact member 9 and a contact at which the contact member 9 comes into contact with the fixing film 1 does not increase.

According to one embodiment, the temperature control device is a temperature control device for controlling temperature of a temperature controlled target to which heat is propagated from a heater by supplying power to the heater, the device including: a temperature estimation unit; a duty generation unit; and a signal generation unit. The temperature estimation unit estimates the temperature of the temperature controlled target based on the duty value. The duty generation unit generates the duty value based on the temperature estimation result by the temperature estimation unit, the temperature detection result of the temperature controlled target by the temperature sensor, and the target temperature. The signal generation unit outputs an energization pulse for controlling the power supplied to the heater based on the duty value.

An image forming apparatus includes: a first image forming unit which forms a first image on a first recording medium with a first material that is not thermally decolorizable; a second image forming unit which forms a second image on a second recording medium with a second material that is thermally decolorizable; a fixing device which is on a common carrying path shared by the first recording medium and the second recording medium and fixes the first image to the first recording medium; and a controller which controls the fixing device so that a temperature of the fixing device is lower than a decolorizing temperature of the second material when the second recording medium reaches the fixing device.